1. Field of the Invention
The present invention relates generally to a Bluetooth® communication method, and in particular, to a dynamic folder browsing method using Bluetooth® to more efficiently pull files in a browsing folder and a system for the same.
2. Description of the Related Art
Bluetooth® is a system for wirelessly interconnecting portable devices including various digital devices in close proximity to each other with low cost. Bluetooth® is a representative wireless communication technology of a personal area network (PAN) for transferring voice and data in communication between various digital devices without physical cable using a radio frequency (RF). For example, by implementing Bluetooth® wireless technology in mobile phones and personal computers (PCs), the mobile phones and PCs can be wirelessly connected, and all digital devices, such as personal digital assistants (PDAs), desktop computers, facsimiles, keyboards, joysticks, and etc, can constitute a part of a Bluetooth® system.
Since Bluetooth® technology supports a low power mode, therefore, it is primarily implemented in portable devices. The use of Bluetooth® technology thereby increases convenience of life. Additionally, since the Bluetooth® technology uses a 2.4 GHz industry scientific medical (ISM) frequency at a maximum 1 Mbps˜3 Mbps rate, additional charge, such as information use charge, does not exist.
Mobile Bluetooth® devices, i.e., mobile communication terminals, perform service, functions corresponding to Bluetooth® service profiles. In particular, data transmission related to file transfer and file browsing is performed according to a File Transfer Profile (FTP). This data transmission process will be described herein with reference to FIG. 1. FIG. 1 illustrates a conventional data flow between a client 10 and a server 20.
As illustrated in FIG. 1, the client 10 can push objects selected by a user to the server 20 and pull selected objects from the server 20. The client 10 must transmit data according to a Generic Object Exchange Profile (GOEP) specification and display folder lists items to the user according to an Object Exchange protocol (OBEX) folder listing format. The server 20 is a target device of the client 10 and must support folder browsing according to an object exchange server and the OBEX folder listing format.
The FTP supports three main functions. A folder browsing function is a function allowing the client 10 to display objects and sub-folders in a root folder of the server 20 from when the client 10 is connected to the server 20. An object transfer function is a function of pulling or deleting selected files or folders after folder browsing is performed. An object operation function defines a series of operations for creating or deleting files or folders in the server 20.
The folder browsing function will now be described in more detail. The folder browsing function can be divided into a process of pulling a file list in a folder and a process of setting a folder to be browsed. FIG. 2 is a signaling diagram illustrating a conventional folder browsing process between the client 10 and the server 20.
In order to pull a file list in a folder, a packet ‘get folder list’ is used, and the file list in the folder can be pulled using a get operation defined in the GOEP. For achieving this result, the client 10 and the server 20, i.e., a user device and a target device, must be connected after a paging process.
Thereafter, referring to FIG. 2 the client 10 accesses a root folder of the server 20 in steps 200 and 210 and pulls a file list in a selected folder from the server 20 in steps 220 to 250. Since the server 20 can transfer data within a range of a transfer amount defined in the FTP, if a file list to be transferred exceeds the transferable amount, the server 20 transfers the file list to the client 10 by dividing the file list in a basis of the transferable amount. Steps 220 to 250 show a process of transferring the file list in twice.
In terms of processing speed of the conventional folder browsing function, if the number of files in a selected folder of the server 20 exceeds, for example, 100, a long time is required for the server 20 to get names of the files and build the file names in a transferable format. In addition, in terms of memory, since the client 10 pulls a total file list from the server 20, the client 10 requires a memory space to store the file list.
As described above, a time delay may occur in terms of processing speed of the conventional folder browsing function. For example, when a user wants to list around 100 files using an extensible markup language (XML) builder of a mobile Bluetooth® device, around 3˜4 seconds are taken. If the user wants to list more than 100 files, folder browsing may fail due to time-out. When the user wants to list more than 400 files, time-out may occur. Furthermore, a parsing process requiring approximately 2˜3 seconds corresponding to half of a builder-speed is necessary in a server. Thus, the greater the number of files to be listed the longer the time taken for file browsing.
In addition, since a client pulls a total file list, if 400 files are pulled, a memory space of 400*512 bytes is necessary in the client, and 400*512 bytes correspond to a data size difficult for a mobile Bluetooth® device having a small memory space to process.